Pure Storage, Inc.

International Business Machines Corporation

Bruno Hennig Cabral

Wesley B Leggette

Ravi V Khadiwala

Ilya Volvovski

Jason K Resch

Manish Motwani

Gary W Grube

Greg R Dhuse

Timothy W Markison

Yogesh Ramesh Vedpathak

Thomas Darrel Cocagne

Michael Colin Storm

Joseph M Kaczmarek

Ethan S Wozniak

Praveen Viraraghavan

Adam Michael Gray

Tyler K Reid

David Brittain Bolen

Peter C Kim

Anuraag Shah

Fnu Manupriya

Sridhar Gopalam

A storage network operates by: issuing read slice requests to storage units of a set of storage units, where the read slice requests identify at least a read threshold number of encoded slices of a set of encoded slices corresponding to a data segment; when less than the read threshold number of encoded slices are received within a time threshold, facilitating receiving a decode threshold number of encoded slices of the set of encoded slices; decoding the decode threshold number of encoded slices to produce recovered encoded data slices, wherein a number of the recovered encoded data slices corresponds to the read threshold number minus a number of the encoded slices received within the time threshold; and outputting the recovered encoded data slices and the encoded slices of the read threshold number of encoded slices received within the time threshold.

Producing recovered data in a storage network

A processing system of a storage network operates by: sending, to at least one storage unit of the storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to data, wherein the data is coded in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of encoded data slices that is required to decode the data; receiving, via the at least one processing circuit and from the at least one storage unit, a first subset of the set of encoded data slices, wherein the first subset is missing at least one missing encoded data slice that was not received from the at least one storage unit in response to the at least one read request and wherein a number of encoded data slices in the first subset is less than the read threshold number; generating, via the at least one processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data generated from a second subset of the set of encoded data slices that includes the at least one missing encoded data slice; and recovering, via the at least one processing circuit, the data based on the at least one rebuilt encoded data slice and the first subset.

Rebuilding missing data in a storage network via locally decodable redundancy data

A computing device includes an interface configured to interface and communicate with a storage network, a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. A computing device receives a data access request for an encoded data slice associated with a data object, determines whether the encoded data slice is stored in the first memory and in response to a determination that the encoded data slice is not stored in the first memory, issues another data access request for the encoded data slice to a second memory, where the first memory includes access characteristics that are faster than the second memory. When a data access response including the encoded data slice is received from the second memory, a response including the encoded data slice is transmitted.

Utilizing memories of different operational speeds in a vast storage network

A storage network operates by: issuing a read threshold number of read slice requests to storage units of a set of storage units, where the read threshold number of read slice requests identifies a read threshold number of encoded slices of a set of encoded slices corresponding to a data segment; when one or more other encoded data slices of the read threshold number of encoded slices is not received within a time threshold, facilitating receiving a decode threshold number of encoded slices of the set of encoded slices; decoding the decode threshold number of encoded slices to produce recovered encoded data slices, wherein a number of the recovered encoded data slices corresponds to the read threshold number minus a number of the encoded slices received within the time threshold; and outputting the recovered encoded data slices and the encoded slices of the read threshold number of encoded slices received within the time threshold.

Generating recovered data in a storage network

Systems and methods for managing conflicting background tasks in a dispersed storage network are provided. In embodiments, a method includes: gathering scheduled future task data for scheduled future tasks from a plurality of task scheduling modules within a dispersed storage network, wherein the scheduled future tasks are tasks associated with stored data objects; monitoring the scheduled future task data for scheduling conflicts based on stored rules; determining that a scheduling conflict exists between a first future task of the scheduled future tasks and a second future task of the scheduled future tasks; issuing instructions to at least one of the plurality of task scheduling modules to update the first future task or the second future task based on the scheduling conflict; and updating, by the at least one of the plurality of task scheduling modules, the first future task or the second future task based on the instructions.

Managing dispersed storage network background tasks

A processing system of a storage network operates by: sending, to at least one storage unit of the storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to a data segment, wherein the data segment is coded in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of slices that is required to decode the data segment; receiving, via the at least one processing circuit and from the at least one storage unit, a first subset of encoded data slices of the set of encoded data slices, wherein the first subset of encoded data slices is missing at least one missing encoded data slice that was not received from the at least one storage unit in response to the at least one read request and wherein the number of encoded data slices in the first subset of the encoded data slices is less than the read threshold number; generating, via the at least one processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data generated from a second subset of the set of encoded data slices that includes the at least one missing encoded data slice; and recovering, via the at least one processing circuit, the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Recovering missing data in a storage network via locally decodable redundancy data

A method for execution by a dispersed storage and task (DST) client module includes issuing a read threshold number of read slice requests are issued to storage units of the set of storage units. One or more encoded slices of a selected read threshold number of encoded slices are received. When a next encoded data slice of a decode threshold number of encoded data slices is received within a response timeframe, outputting of the next encoded data slice is initiated. When the next encoded data slice is not received within the response timeframe, receiving of another decode threshold number of encoded slices of the set of encoded slices is facilitated. The other decode threshold number of encoded slices are decoded to produce recovered encoded data slices, where the recovered encoded data slices includes at least a recovered next encoded data. Outputting of the recovered next encoded data slice is initiated.

Retrieving data in a storage network

A network storage system operates by: sending, to at least one storage unit of a storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to a data segment, wherein the data segment is codable in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of slices that is required to decode the data segment; receiving from the at least one storage unit, a first subset of encoded data slices of the set of encoded data slices, wherein the first subset of encoded data slices is missing at least one missing encoded data slice from the number of the set of slices that is required to decode the data segment and that was not received from the at least one storage unit in response to the at least one read request; generating at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data includes a plurality of local redundancy slices generated from a second subset of the set of encoded data slices that includes the at least one missing encoded data slice; and recovering the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Utilizing locally decodable redundancy data in a vast storage network

In various embodiments, a method is presented for execution by a processing circuit of a storage network device that includes a processor. The method comprises: receiving, via the processing circuit, a first subset of encoded data slices of a set of encoded data slices corresponding to a data segment; identifying, via the processing circuit, at least one missing encoded data slice of the first subset of slices that is required to decode the data segment; generating, via the processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data; and recovering, via the processing circuit, the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Rebuilding data via locally decodable redundancy in a vast storage network

A computing device includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. A computing device receives a data access request for an encoded data slice (EDS) associated with a data object. The computing device compares a slice name of the data access request with slice names stored within RAM. When the data access request slice name compares unfavorably with those stored slice names, the computing device transmits an empty data access response that includes no EDS to the other computing device without needing to access a hard disk drive (HDD) that stores EDSs. Alternatively, the computing device transmits a data access response that includes the EDS.

Storage unit including memories of different operational speeds for optimizing data storage functions

Recovering data in a storage network

A method begins by a processing module of a dispersed storage network (DSN) determining a fault domain for a portion of the DSN and generating a local redundancy for the fault domain. The method continues with the processing module identifying storage locations available for storing the first local redundancy, selecting storage locations for storing the first local redundancy and continues with the processing module facilitating storage of the local redundancy in the storage locations. Upon detecting a storage failure in the DSN, the method continues with the processing module determining whether the storage failure is associated with the fault domain and in response determining whether the first local redundancy is associated with the first fault domain. In response to determining that the local redundancy is associated with the first fault domain the method continues with the processing module recovering the local redundancy and correcting the storage failure.

Reliably recovering stored data in a dispersed storage network

Utilizing fast memory devices to optimize different functions

A method for execution by a dispersed storage and task (DST) execution unit includes identifying a plurality of pending operations. A resource availability level to support execution of at least one of the plurality of pending operations is determined, and a required resource level to execute the at least one of the plurality of pending operations is determined. A balance factor between at least two types of the plurality of pending operations is determined based on the resource availability level and the required resource level. Determination of required timing of the execution of the at least one of the plurality of pending operations is coordinated with at least one other DST execution unit. An operation execution schedule is updated based on the required resource levels, the resource availability level, the balance factor, and the required timing of the execution.

Establishing an operation execution schedule in a storage network

A method for execution by a dispersed storage and task (DST) client module includes issuing a read threshold number of read slice requests are issued to storage units of the set of storage units. One or more encoded slices of a selected read threshold number of encoded slices are received. When a next encoded data slice of a decode threshold number of encoded data slices is received within a response timeframe, outputting of the next encoded data slice is initiated. When the next encoded data slice is not received within the response timeframe, receiving of another decode threshold number of encoded slices of the set of encoded slices is facilitated. The other decode threshold number of encoded slices are decoded to produce recovered encoded data slices, where the recovered encoded data slices includes at least a recovered next encoded data.

Growing community of inventors

Chicago, IL, United States of America

Bruno Hennig Cabral